On Wed, Sep 22 2021, Carlo Arenas wrote: > On Wed, Sep 22, 2021 at 6:41 PM brian m. carlson > <sandals@xxxxxxxxxxxxxxxxxxxx> wrote: > >> > diff --git a/Makefile b/Makefile >> > index 9df565f27b..d5c6d0ea3b 100644 >> > --- a/Makefile >> > +++ b/Makefile >> > @@ -1302,7 +1302,7 @@ GENERATE_COMPILATION_DATABASE = no >> > endif >> > >> > ifeq ($(GENERATE_COMPILATION_DATABASE),yes) >> > -compdb_check = $(shell $(CC) $(ALL_CFLAGS) \ >> > +compdb_check = $(shell $(CC) \ >> > -c -MJ /dev/null \ >> > -x c /dev/null -o /dev/null 2>&1; \ >> > echo $$?) >> >> Are you sure this results in a functional set of files? > > no; it does not > > This call is only meant to be used to check if your compiler supports > the feature (which as Ævar points out[1], might not be the best thing > to do in this case), though > > After this fix the files are being generated (in a different place > with their expected flags) and look healthy, but would be helpful to > know you see no regressions. I had the same thought as brian, but you're right, since we never use the result of this it's OK. IOW this check is really functionally equivalent to something like: cc --help | grep -q -F -- -MJ Or whatever, i.e. we're just checking if it's clang & supports the -MJ option. > [1] https://lore.kernel.org/git/87tuic5cdo.fsf@xxxxxxxxxxxxxxxxxxx/